Excess of light can be polluting tooSeptember 10th, 2008 - 12:05 pm ICT by IANS
Washington, Sep 10 (IANS) Excess of illumination at night can compromise sleep and cause problems for stargazing and animal health. Balancing public and private interests for lighting has been a difficult undertaking. Too little lighting can compromise safety and security, too much of it may cause problems for human well being.
Scientists at the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute have developed the first ever comprehensive method for measuring various aspects of light pollution. Their methods were described recently in the journal of Lighting Research Technology.
Called outdoor site-lighting performance (OSP), the method allows users to quantify - and thus optimise - the performance of existing and planned lighting designs.
“Until now the conversation about light pollution has been just that - a lot of talk with no data,” said Mark Rea, LRC director and principal investigator on the project.
“The LRC’s OSP measurement method is a powerful tool, allowing users to address three important aspects of light pollution - sky glow, light trespass, and discomfort glare - quantitatively and at the same time.”
Sky glow is defined as total amount of light leaving a property. Light trespass describes the amount of light crossing from one property boundary onto another, and discomfort glare predicts the level at which light coming from a source is uncomfortable for viewers.
Although the three factors are independent of one another, each is measured using OSP, allowing users to control and maximise the positive benefits of nighttime lighting, while minimising their negative effects, according to Rea.